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Zipvit Sport Nutrition Guide for Long Swims

22nd July 2015

Endurance sports not only require you to follow a structured plan and carry out a certain volume of training but the key to success may also ultimately come from a carefully tailored nutrition plan. Hydration, Energy and Recovery are the 3 fundamental aspects.

Depleted Hydration and/or Carbohydrates (CHO) are the two main factors influencing early fatigue and impaired performance during endurance sports (both physical and mental). Maintaining adequate fluid and CHO intake helps to optimise performance.

Hydration

Unless fluid losses are replaced by drinks, sweating causes progressive depletion of circulating blood volume. This leads to a thickening of the blood and places a strain on the cardiovascular system, with a rise in heart rate in order to maintain adequate blood flow to exercising muscles and vital organs.

A loss of 2% bodyweight (just 1kg for a 50kg person) causes an increase in perceived effort and is claimed to reduce performance by 10-20%.

The American College of Sports Medicine recommends drinking 400 to 600ml approximately 2 hours before exercise. An additional 200 to 300ml should be consumed between 10 and 20 minutes before the start of the event. This allows for water to enter the circulation as the race begins and improves gastric emptying (the ability of the stomach to digest fluids) *fluids leave the stomach faster when gastric volume is high compared to when the volume is low.

Sweat rates vary so widely, a worthwhile plan is to record fluid intake during training or events (also noting the weather conditions) and weighing, without clothes, before and after, to assess how much fluid intake you need. It is difficult to replace all of the fluids lost as sweat. Partial fluid replacement is the goal.

Energy

Carbohydrates are the main source of fuel for endurance sports. Longer or high intensity events require more energy. Taking on carbohydrates during exercise maintains blood glucose concentrations and provides extra fuel, thus sparing your body’s carbohydrate stores (glycogen). This extra carbohydrate might be consumed in a sports drink, energy gel or an energy bar. Amounts will vary with exercise intensity, the duration, and your own individual tolerance.

A guideline for recreational endurance athletes is 30g-60g of carbs per hour for low to moderate intensity racing. Research suggests that 60g-90g of carbohydrate per hour is optimal for high intensity/long duration activities. This can be adjusted according to how your body reacts.

In the hour before the start, drink up to 400ml ZV1 Energy Drink and a ZV8 Energy Bar. This will give you approx 60g of CHO which will be utilised during the initial hour.

Try to save energy gels for the end of the swim when you are at the bottom of your energy stores and finding it hard to eat. Generally aim for 50% of your calories to come from liquids or semi-solid gels and 50% from solids which may include a ZV8 Energy Bar, sandwich or banana etc.

Fluid and CHO strategies should then be tailored to the individual depending on intensity, duration and climatic conditions. *In hot conditions it may be possible to drink enough CHO to fuel your race – see table below…

After prolonged exercise muscle enzymes that support glycogen production are elevated. Your muscles are more receptive and can absorb up to 50% more glycogen than at any other time.

Consuming carbohydrates within the first 30 minutes following exercise has been shown to optimise recovery. Protein is an equally important component of recovery to repair the damaged muscle and to build new muscle tissue. A ZV9 Protein Recovery Bar which contains 20g of whey protein and 25g of carbohydrates is perfect for this.

Zipvit Sport have a whole range of high performance energy products perfect for before, during and after your training or event. At any Human Race Swim there will be Zipvit Sport energy products on offer. You can try some beforehand by taking advantage of our special 25% discount by using the code ‘HR1’ at the checkout when shopping at www.zipvitsport.co.uk.